It's a 20-year trend. One that has continued, despite a recession when people expect crime to pick up.

All Things Considered's Robert Siegel spoke to Frank Scafidi, director of public affairs for the National Insurance Crime Bureau and a former FBI agent, to ask him why.

First Scafidi points out, "there isn't empirical evidence to make the case" that crime picks up during tough economic times. Scafidi says it didn't even happen during the Great Depression.

Now, Scafidi mostly deals with auto theft and he has convincing, simple explanations for why that kind of crime is down:

-- First, technology: A 2011 car is much harder to steal than a car from the '90s. They have all kinds of technology to help locate the car and simply make it harder to drive off with.

"For a lot of auto thieves, it's just not worth it," he told Robert.

-- Second, police now set up bait cars and have the help of license plate readers, which increase the risk for auto thieves.

-- Third, said Scafid,i it might be an issue of reporting. As police departments slash budgets, there are fewer officers to take crime reports. How many people, said Scafidi, will take the time to complete a police report online? How many will just give up and the crime goes unreported?

As for the broader drop in crime, Scafidi says he likes to take the optimistic view.

"I like to think people are pulling less and less of these crimes. Maybe they're finding that the upside of it isn't that all that high, that the risk is not greater than the reward and are just letting those sorts of behaviors alone," he said.

He said the drop in crime had to do with better policing. CBS News reports:

"'In the 1990s, policing got it right," Bratton told "Early Show" anchor Chris Wragge. 'We began to focus once again on preventing crime; '60s, '70s, '80s, we focused on responding to crime. It's a lot different to try to prevent it, and we've become very successful at preventing it.'

"Northeastern University criminologist James Alan Fox disputes the popular myth that crime should be going up in a bad economy.

"'They're using technology; they're using data, crime patterns, maps to figure out where are the hot spots, what's the trend in terms of crime and trying to be proactive,' Fox said of law enforcement agencies. 'People are either criminals or not, independent of whether they have a job.'"

All Things Considered will have much more of Robert's conversation with Scafidi on tonight's edition. Tune in to your local NPR member station to listen. We'll also post the as-aired version of the interview at the top of this post, later today.